Data storage systems typically include one or more physical storage processors (SPs) accessing an array of disk drives and/or electronic flash drives. Each SP is connected to a network, such as the Internet and/or a storage area network (SAN), and receives transmissions over the network from host computing devices (“hosts”). The transmissions from the hosts include “IO requests,” also called “host IOs.” Some IO requests direct the SP to read data from an array, whereas other IO requests direct the SP to write data to the array. Also, some IO requests perform block-based data requests, where data are specified by LUN (Logical Unit Number) and offset values, whereas others perform file-based requests, where data are specified using file names and paths. Block-based IO requests typically conform to a block-based protocol, such as Fibre Channel or iSCSI (Internet SCSI, where SCSI is an acronym for Small Computer System Interface), for example. File-based IO requests typically conform to a file-based protocol, such as NFS (Network File System), CIFS (Common Internet File System), or SMB (Server Message Block), for example.
In some data storage systems, an SP may operate one or more virtual data movers. As is known, a virtual data mover is a logical grouping of file systems and servers that is managed by the SP and provides a separate context for managing host data stored on the array. A single SP may provide multiple virtual data movers for different users or groups. For example, a first virtual data mover may organize data for users in a first department of a company, whereas a second virtual data mover may organize data for users in a second department of the company. Each virtual data mover may include any number of host file systems for storing user data.
It should be understood that a first set of virtual data movers may utilize a first pool of storage formed by a first set of storage drives (e.g., flash drives, magnetic disk drives, etc.), and a second set of virtual data movers may utilize a second pool of storage formed by a second set of storage drives. If storage drives are added to the first pool of storage drives, the first set of virtual data movers is able to access more storage. Likewise, if storage drives are added to the second pool of storage drives, the second set of virtual data movers is able to access more storage.